The Sturmtiger was based on the late model Tiger I, keeping its hull and suspension. The front of the Tiger's superstructure was removed to make room for the new fixed casemate-style fighting compartment housing the rocket launcher. This was located directly at the front of the vehicle, giving it a boxy appearance.
Compared to the regular Tiger tank, the Sturmtiger was much shorter, only 6.28 metres (20 ft 7 in) compared to the Tiger's 8.45 metres (27 ft 9 in), due largely to the fact that it did not mount the protruding main gun of the latter. It also was slightly lower than the Tiger, 2.85 metres (9 ft 4 in) compared to 3 metres (9 ft 10 in).
| Sturmmörserwagen 606/4 mit 38 cm RW 61 | |
|---|---|
| Type | Heavy assault gun |
| Place of origin |  Nazi Germany |
| Service history | |
| In service | August 1944 - 1945 |
| Wars | World War II |
| Production history | |
| Designer | Alkett |
| Designed | 1943–1944 |
| Manufacturer | Alkett |
| Produced | October 1943 – January 1945 |
| Number built | 19 (1 prototype and 18 production) |
| Specifications | |
| Weight | 68 tonnes (75 short tons; 67 long tons) |
| Length | 6.28 metres (20 ft 7 in) |
| Width | 3.57 metres (11 ft 9 in) |
| Height | 2.85 metres (9 ft 4 in) |
| Crew | 5 driver machine gunner / radio operator loader 2nd loader commander / gunner |
| | |
| Armor | max. 150 mm (superstructure front, at 47° from vertical) min. 62 mm |
| Main armament | 380 mm RW 61 rocket launcher L/5.4 (14 rounds, up to 376 kg each) |
| Secondary armament | 100 mm grenade launcher (using SMi 35 leaping mines) 7.92 x 57 mm MG 34 machine gun |
| Engine | V-12, water-cooled Maybach HL230P45 engine 700 PS (690 hp, 515 kW) |
| Power/weight | 10,77 PS/tonne |
| Suspension | torsion-bar |
| Operational range | 120 kilometres (75 mi) |
| Speed | 40 kilometres per hour (25 mph) |
Sturmtiger Armour
Since the Sturmtiger was intended for use in urban areas in close range street fighting, it needed to be heavily armoured to survive. Its sloped (at 47° from vertical) frontal armour therefore was 150 millimetres (5.9 in) thick, while its superstructure side and rear plates were some 82 millimetres (3.2 in) thick. The hull front, depending on whether or not it had an additional armor plate, was 150 millimetres (5.9 in) or 100 millimetres (3.9 in). This pushed the weight of the vehicle up from the 57 tonnes (56 long tons; 63 short tons) of the Tiger I to 68 tonnes (67 long tons; 75 short tons).
| Armour thickness | Location | Slope (angle from vertical) |
|---|---|---|
| 150 mm | superstructure front | 47° |
| 150 mm 100 mm | hull front (with / without the additional armor plate) | |
| 82 mm | superstructure side and rear & upper hull side and rear | |
| 70 mm | hull front top | 80° |
| 62 mm | lower hull front | 65° |
| 62 mm | lower hull side and rear |
Sturmtiger Weapons
The main armament was the 380 mm Raketen-Werfer 61 L/5.4, a breech-loading rocket launcher, which fired short-range, rocket-propelled projectiles roughly 1.5 metres (59 in) long. There were a variety of rounds with a weight of up to 376 kilograms (830 lb), and a maximum range of up to 6000 metres, which either contained a high explosive charge of 125 kilograms (280 lb) or a shaped charge for use against fortifications, which could penetrate up to 2.5 metres (98 in) of reinforced concrete. The stated range of the former was 5,650 metres (6,180 yd). A normal charge first accelerated the projectile to 45 metres per second (150 ft/s), the 40 kilograms (88 lb) rocket charge then boosted this to about 250 m/s (820 ft/s).
The design of the rocket launcher caused some problems. The hot rocket exhaust could not be vented into the fighting compartment but nor could the barrel withstand the pressure if the gasses were not vented. Therefore a ring of ventilation shafts were put around the barrel which channeled the exhaust and gave the weapon somewhat of a pepperbox appearance.
Due to the bulkiness of the ammunition, only 14 rounds could be carried, of which one was already loaded, with another in the loading tray. The rest were carried in two storage racks. To help with the loading of ammunition into the vehicle, a loading crane was fitted at the rear of the superstructure, next to the loading hatch. Even then, the entire five man crew had to help with the loading.
It was intended that each Sturmtiger would be accompanied by an ammunition carrier built on the same Tiger I chassis, but only one carrier was completed.
At the loading hatch's rear was located a 100 millimetres (3.9 in) grenade launcher, using SMi 35 leaping mines, which was used for close range defence against both armoured vehicles and infantry in a 360 degree circle around the vehicle.
For defence against infantry attacks, there was a mount in the front for a 7.92 x 57 mm MG 34 machine gun.
